Programmable identifiers such as RFID (Radio Frequency Identification) and NFC (Near Field Communication) tags are commonplace in many applications, particularly in customer/user based applications such as retail sales and inventory management.
Typically, a programmable tag is fixed or otherwise embedded into an article to be monitored or tracked. This can be, for example: via a removable security device that may be adhered to a book, clipped to garments etc. to prevent theft from shops; affixed to a box or interior of an item via an adhesive pad or similar or the tag may be integrated into the item or packaging during manufacture.
A programmable tag typically includes an antenna coupled to some form of memory. The memory can be interrogated and in some cases altered via appropriate signals received by the antenna.
Tracking and interrogation of tags can be done in many ways, although typical methods are via use of hand-held scanner type devices at checkouts/point of receipt or departure and via readers positioned in premises such that a tag must pass through them (for example by the door of a shop or the like). Actions taken when a tag is encountered vary depending on application. For example—in package tracking it may just be to record when the package entered or left a facility or vehicle. In retail, the passage of a tag through a portal typically causes an alarm to be sounded (because tags are typically removed or disabled at the point of sale).
One particular application where programmable identifiers are in frequent use and are also frequently programmed and reprogrammed to show loan status is in lending libraries where a tag may be used to identify a book or other item being borrowed or returned and link to the lender's account to identify fines due and the like. In such cases, attributes of the tag are also used to identify whether the item has been successfully lent and can be allowed off-premises. Often the check-out procedure is done by the user via a kiosk or similar without staff interaction so the user may be responsible for correctly “programming” the tag (positioning it so the kiosk can read it and write to it).
During the early implementation of RFID and similar tags, at least some of the security they provided was through obscurity—nobody could read or write to them without the appropriate (typically bespoke) hardware and software.
However, this is no longer the case, particularly with the advent of NFC capable smart phones.